Lin Guowen, Sheng Haoyue, Xie Huyang, Zheng Qiupeng, Shen Yijun, Shi Guohai, Ye Dingwei
Department of Urology, Fudan University Shanghai Cancer Center, Shanghai 200032, P.R. China.
Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China.
Oncol Lett. 2019 Mar;17(3):3537-3547. doi: 10.3892/ol.2019.9970. Epub 2019 Jan 25.
Circular RNAs (circRNAs) are a specific form of non-coding RNAs, that serve a pivotal role in the development of human diseases, including Alzheimer's disease and cancer; however, only a few are known with respect to cancer. The present study identified a novel circRNA, circ lysophosphatidic acid receptor 1 (LPAR1) (hsa_circ_0087960), derived from two exons 226 base pairs in length, in muscle-invasive bladder cancer (MIBC) tissues. circLPAR1 was identified to be lowly expressed in MIBC tissues in a cohort of 125 cases, and predicted a poor disease-specific survival time, compared with patients with high circLPAR1 expression (52.4 vs. 56.0 months; P=0.001) by univariate and multivariate Cox regression analyses. Matrigel and wound healing assays also demonstrated that the invasion of 5637 and T24 bladder cancer cells were significantly enhanced following the knockdown of circLPAR1 by small interfering RNA (si-circLPAR1-1 in T24 cell line, P=0.01; si-circLPAR1-2 in 5637 cell line, P=0.003; si-circLPAR1-2 in T24 cell line, P=0.002; si-circLPAR1-2 in 5637 cell line, P=0.006). The bioinformatics analysis indicated that circLPAR1 may harbor specific microRNAs (miRNAs) according to the miRNAs seed sequence matching. A luciferase reporter assay revealed that miR-762 can inhibit the activity of the transfected luciferase gene when inserted in a circLPAR1 wild-type fragment, and this inhibition could be alleviated when the luciferase gene was inserted in a circLPAR1 fragment with the mutated miR-762 target site. In conclusion, the circLPAR1 may function as a potential novel and stable biomarker for the prognosis of MIBC and may be associated with the invasion and metastasis by miR-762.
环状RNA（circRNAs）是非编码RNA的一种特殊形式，在包括阿尔茨海默病和癌症在内的人类疾病发展中起关键作用；然而，关于癌症的环状RNA却知之甚少。本研究在肌肉浸润性膀胱癌（MIBC）组织中鉴定出一种新型环状RNA，即环磷酸溶血磷脂酸受体1（LPAR1）（hsa_circ_0087960），其由两个长度为226个碱基对的外显子衍生而来。在125例病例队列中，circLPAR1在MIBC组织中低表达，单因素和多因素Cox回归分析显示，与circLPAR1高表达患者相比，其疾病特异性生存时间较差（52.4个月对56.0个月；P=0.001）。基质胶和伤口愈合实验还表明，通过小干扰RNA敲低circLPAR1后（T24细胞系中的si-circLPAR1-1，P=0.01；5637细胞系中的si-circLPAR1-2，P=0.003；T24细胞系中的si-circLPAR1-2，P=0.002；5637细胞系中的si-circLPAR1-2，P=0.006），5637和T24膀胱癌细胞的侵袭能力显著增强。生物信息学分析表明，根据微小RNA（miRNA）种子序列匹配，circLPAR1可能含有特定的miRNA。荧光素酶报告基因实验显示，当插入circLPAR1野生型片段时，miR-762可抑制转染的荧光素酶基因活性，而当荧光素酶基因插入具有突变miR-762靶位点的circLPAR1片段时，这种抑制作用可得到缓解。总之，circLPAR1可能作为MIBC预后的一种潜在新型稳定生物标志物，并且可能与miR-762介导的侵袭和转移有关。
